AlgoExpert Monotonic Array

def isMonotonic(array):
    firstChangeIndex = 1
    isIncreasing = True
    for i in range(1, len(array)):
        if (i == firstChangeIndex):
            if array[i] < array[i-1]:
                isIncreasing = False
                firstChangeIndex = -1
            elif array[i] > array[i-1]:
                isIncreasing = True
                firstChangeIndex = -1
        if firstChangeIndex != -1:
            firstChangeIndex += 1
        
        else:
            if (array[i] > array[i-1] and not isIncreasing) or (array[i] < array[i-1] and isIncreasing):
                return False
    return True